can't get 18650 battery to power ESP32

[au_nel]

Hi all,

I've got two ESP32s: one acting as the sender node with 3 sensors (DHT22, MQ-2, and MQ-7) connected to its 5V and GND pin, the other acting as the receiver node. The two ESP32s are communicating through ESPNOW and the receiver node is connected to the wifi to upload the sensor values to Thingspeak.

So I tried powering the sender node with one 18650 battery with a 5V booster through its 5V pin but it didn't work. The receiver node isn't receiving new values from the sensors. Also, before connecting the booster to the ESP32, its output voltage was at 5.04V and it became 3.43V after connecting it. So I thought maybe because I had 3 sensors connected to it that it didn't work so I tried the battery on the receiver node (sorry if that was a dumb reasoning, I haven't really used an ESP32 before). The output voltage was still at 5V when I connected it to the receiver node but it wasn't sending any of the values to Thingspeak.

What am I doing wrong? Should I change the power supply?

Btw, not sure if this helps, both ESP32s work when I power it using the micro usb and its voltage is around 4V.

Thanks!
Nelle

[vanBassum]

Is the booster capable of derlivering enough current?
Another thing to check, some booster boards have an enable pin.

[au_nel]

The current I measured from the booster to the sender node was 0.2 A. Is this enough?

I soldered the pads next to A and B, as the instructions said, to get 5V output on the booster. I don't think there's an enable pin.
This is the booster I am using:

[au_nel]

Sorry, correction to this part:

I soldered the pads next to A and B, as the instructions said, to get 5V output on the booster.

Its supposed to be "I broke apart the pads next to A and B using a soldering iron, as the instructions said, to get 5V output on the booster."

[vanBassum]

Are you using lipo with a protectionboard?
Otherwise your lipo meight get damaged since there is no undervoltage protection.

Accoding to your screenshot this booster should be able to deliver 1A max so, 0.2A shouln't be a problem. Altough I would expect the output of this booster to have a very diry signal. Also, specs on websites like aliexpress shouldn't taken to seriousely.

To be fair, I would suggest you to use another booster board, something a bit more suitable to your application. You could buy one of those cheap usb charger things that use one lipo cell.

[au_nel]

No, I'm not using any protection board. Is that any different from a charging module/board like the screenshot below?

tp4056 charger module.jpg (143.16 KiB) Viewed 5280 times

Do you know any good booster board that could (hopefully) work on the sender node?

I did think of buying a cheap 2600 mah powerbank to power the receiver node if I can't make it work using a booster since it worked when I plugged it to my powerbank.

[vanBassum]

The board in your last post has a protection circuit. So that is more suitable for you.
Altough its better suited, im not sure if it will fix your initial problem.